sustainability

Why GREEN ROOFS for South Africa?

Large scale roof planting will reduce the 'urban heat island effect' and improve the flow of cool fresh air into the city. The impervious surfaces of cities such as concrete, tarmac and the wide variety of roof surfaces soak up solar energy and reradiate it as thermal infrared radiation (heat). The result of this is that cities are warmer both day and night than the surrounding countryside. This can have profoundly negative effects on air quality in the city. Production of some pollutants can be higher and the flushing out of others is reduced as the inflow of clean cool air is reduced by the thermal conditions.

Airborne particulate pollutants are deposited in the substrate, on the leaf surfaces of the plant layer, and onto the moist internal surfaces of the leaf.